Influence of Phenotypes on Short-Term Outcomes in Hospitalized Heart Failure with Preserved Ejection Fraction—Insights from a North-Eastern Romanian Cohort

Background/Objectives: There are significant gaps in knowledge regarding the heterogeneity of heart failure (HF) phenotypes, particularly among patients with preserved left ventricular ejection fraction (HFpEF). Our aim was to identify phenotypes within the hospitalized North-Eastern Romanian HFpEF cohort and their impact on short-term outcomes. Methods and Results: We derived a cluster model from 924 patients with HFpEF hospitalized over an 18-month interval in the Internal Medicine II Department of the “Sf. Spiridon” Emergency Clinical County Hospital in Iași, Romania. The median age of the patients was 74 years [range 30–101], 59.8% were women, and the most frequent comorbidities were arterial hypertension (93.2%), valvular heart disease (68.7%), atherosclerotic cardiovascular disease (ASCVD, 64.6%) and atrial fibrillation (43%). Statistical analysis identified five distinct phenotypes: cluster 1 (21.6% of patients) consisted of normal-weight patients with valvular disease predominance; cluster 2 (18.2%) described a severe cardiometabolic phenotype; cluster 3 (19.6%) defined a young, hypertensive, and atherosclerotic phenotype; cluster 4 (21.26%) described a hypertensive–atrial fibrillation phenotype; and cluster 5 (18.9%) included elderly, hypertensive non-diabetic patients with severe vascular burden (ASCVD 100%). Conclusions: This study defines five distinct phenotypes within the HFpEF population in our region which differ in terms of clinical characteristics and heart failure pharmacological therapy. These results confirm the significant heterogeneity of HFpEF. The identified phenotypes were not associated with significant differences in composite short-term outcomes, including in-hospital mortality and 30-day rehospitalization for heart failure.